Cellulosic and lignocellulosic materials and compositions and composites made therefrom

ABSTRACT

Cellulosic or lignocellulosic materials, and compositions and composites made therefrom, are disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/337,580, filed Jun. 22, 1999, which is a continuation inpart of U.S. patent application Ser. No. 08/961,863, filed Oct. 31,1997, now issued as U.S. Pat. No. 5,973,035; is a continuation-in-partof U.S. patent application Ser. No. 09/338,209, filed Jun. 22, 1999,which is a continuation-in-part of U.S. patent application Ser. No.08/921,807, filed Sep. 2, 1997, now issued as U.S. Pat. No. 5,952,105;and is a continuation in part of U.S. patent application Ser. No.09/290,031, filed Apr. 9, 1999, which is a division of U.S. patentapplication Ser. No. 08/961,863, filed Oct. 31, 1997, now issued as U.S.Pat. No. 5,973,035.

BACKGROUND OF THE INVENTION

The invention relates to texturized cellulosic or lignocellulosicmaterials and compositions and composites made from such texturizedmaterials.

Cellulosic and lignocellulosic materials are produced, processed, andused in large quantities in a number of applications. Once used, thesematerials are usually discarded. As a result, there is anever-increasing amount of waste cellulosic and lignocellulosic material.

SUMMARY OF THE INVENTION

In general, the invention features texturized cellulosic orlignocellulosic materials and compositions and composites madetherefrom.

In one embodiment, the invention features a process for preparing atexturized fibrous material. The process involves shearing a cellulosicor lignocellulosic material having internal fibers (e.g., flax; hemp;cotton; jute; rags; finished or unfinished paper, paper products,including poly-coated paper, or byproducts of paper manufacturing suchas pulp board; or synthetic cellulosic or lignocellulosic materials suchas rayon), to the extent that the internal fibers are substantiallyexposed, resulting in texturized fibrous material. The cellulosic orlignocellulosic material can be a woven material such as a woven fabric,or a non-woven material such as paper or bathroom tissue. The exposedfibers of the texturized fibrous material can have a length/diameter(L/D) ratio of at least about 5 (at least about 5, 10, 25, 50, or more).For example, at least about 50% of the fibers can have L/D ratios ofthis magnitude.

In another embodiment, the invention features a texturized fibrousmaterial that includes a cellulosic or lignocellulosic material havinginternal fibers, where the cellulosic or lignocellulosic material issheared to the extent that the internal fibers are substantiallyexposed.

The texturized fibrous material can, for example, be incorporated into(e.g., associated with, blended with, adjacent to, surrounded by, orwithin) a structure or carrier (e.g., a netting, a membrane, a flotationdevice, a bag, a shell, or a biodegradable substance). Optionally, thestructure or carrier may itself be made from a texturized fibrousmaterial (e.g., a texturized fibrous material of the invention), or of acomposition or composite of a texturized fibrous material.

The texturized fibrous material can have a bulk density less than about0.5 grams per cubic centimeter, or even less than about 0.2 g/cm³.

Compositions that include the texturized fibrous materials describedabove, together with a chemical or chemical formulation (e.g., apharmaceutical such as an antibiotic or contraceptive, optionally withan excipient; an agricultural compound such as a fertilizer, herbicide,or pesticide; or a formulation that includes enzymes) are also withinthe scope of the invention, as are compositions that include thetexturized fibrous materials and other liquid or solid ingredients(e.g., particulate, powdered, or granulated solids such as plant seed,foodstuffs, or bacteria).

Composites that include thermoplastic resin and the texturized fibrousmaterials are also contemplated. The resin can be, for example,polyethylene, polypropylene, polystyrene, polycarbonate, polybutylene, athermoplastic polyester, a polyether, a thermoplastic polyurethane,polyvinylchloride, or a polyamide, or a combination of two or moreresins.

In some cases, at least about 5% by weight (e.g., 5%, 10%, 25%, 50%,75%, 90%, 95%, 99%, or about 100%) of the fibrous material included inthe composites is texturized.

The composite may include, for example, about 30% to about 70% by weightresin and about 30% to about 70% by weight texturized fibrous material,although proportions outside of these ranges may also be used. Thecomposites can be quite strong, in some cases having a flexural strengthof at least about 6,000 to 10,000 psi.

In another embodiment, the invention features a composite including aresin, such as a thermoplastic resin, and at least about 2% by weight,more preferably at least about 5% by weight, texturized cellulosic orlignocellulosic fiber. The invention also features a composite thatincludes polyethylene and at least about 50% by weight texturizedcellulosic or lignocellulosic fiber.

The invention further features composites, including a resin andcellulosic or lignocellulosic fiber, that have flexural strengths of atleast about 3,000 psi, or tensile strengths of at least about 3,000 psi.

In addition, the invention features a process for manufacturing acomposite; the process includes shearing cellulosic or lignocellulosicfiber to form texturized cellulosic or lignocellulosic fiber, thencombining the texturized fiber with a resin. A preferred method includesshearing the fiber with a rotary knife cutter. The invention alsofeatures a process for manufacturing a composite that includes shearingcellulosic or lignocellulosic fiber and combining the fiber with aresin.

The composites can also include inorganic additives such as calciumcarbonate, graphite, asbestos, wollastonite, mica, glass, fiber glass,chalk, talc, silica, ceramic, ground construction waste, tire rubberpowder, carbon fibers, or metal fibers (e.g., stainless steel oraluminum). The inorganic additives can represent about 0.5% to about 20%of the total weight of the composite.

The composite can be in the form of, for example, a pallet (e.g., aninjection molded pallet), pipes, panels, decking materials, boards,housings, sheets, poles, straps, fencing, members, doors, shutters,awnings, shades, signs, frames, window casings, backboards, wallboards,flooring, tiles, railroad ties, forms, trays, tool handles, stalls,bedding, dispensers, staves, films, wraps, totes, barrels, boxes,packing materials, baskets, straps, slips, racks, casings, binders,dividers, walls, indoor and outdoor carpets, rugs, wovens, and mats,frames, bookcases, sculptures, chairs, tables, desks, art, toys, games,wharves, piers, boats, masts, pollution control products, septic tanks,automotive panels, substrates, computer housings, above and below-groundelectrical casings, furniture, picnic tables, tents, playgrounds,benches, shelters, sporting goods, beds, bedpans, thread, filament,cloth, plaques, trays, hangers, servers, pools, insulation, caskets,bookcovers, clothes, canes, crutches, and other construction,agricultural, material handling, transportation, automotive, industrial,environmental, naval, electrical, electronic, recreational, medical,textile, and consumer products. The composites can also be in the formof a fiber, filament, or film.

The terms “texturized cellulosic or lignocellulosic material” and“texturized fibrous material” as used herein, mean that the cellulosicor lignocellulosic material has been sheared to the extent that itsinternal fibers are substantially exposed. At least about 50%, morepreferably at least about 70%, of these fibers have a length/diameter(L/D) ratio of at least 5, more preferably at least 2.5, or at least 50.An example of texturized cellulosic material is shown in FIG. 1.

The texturized fibrous materials of the invention have properties thatrender them useful for various applications. For example, the texturizedfibrous materials have absorbent properties, which can be exploited, forexample, for pollution control. The fibers are generally biodegradable,making them suitable, for example, for drug or chemical delivery (e.g.,in the treatment of humans, animals, or in agricultural applications).The texturized fibrous materials can also be used to reinforce polymericresins.

Those composites that include texturized fibrous material and resin arestrong, lightweight, and inexpensive. The raw materials used to make thecomposites are available as virgin or recycled materials; for example,they may include discarded containers composed of resins, and wastecellulosic or lignocellulosic fiber.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a photograph of a texturized newspaper, magnified fifty times.

DETAILED DESCRIPTION OF THE INVENTION

Examples of cellulosic raw materials include paper and paper productssuch as newsprint, poly-coated paper, and effluent from papermanufacture; examples of lignocellulosic raw materials include wood,wood fibers, and wood-related materials, as well as materials derivedfrom kenaf, grasses, rice hulls, bagasse, cotton, jute, other stemplants (e.g., hemp, flax, bamboo; both bast and core fibers), leafplants (e.g., sisal, abaca), and agricultural fibers (e.g., cerealstraw, corn cobs, rice hulls, and coconut hair). Aside from virgin rawmaterials, post-consumer, industrial (e.g., offal), and processing waste(e.g., effluent) can also be used as fiber sources.

Preparation of Texturized Fibrous Material

If scrap cellulosic or lignocellulosic materials are used, they shouldbe clean and dry. The raw material can be texturized using any one of anumber of mechanical means, or combinations thereof. One method oftexturizing includes first cutting the cellulosic or lignocellulosicmaterial into ¼- to ½-inch pieces, if necessary, using a standardcutting apparatus. Counter-rotating screw shredders and segmentedrotating screw shredders such as those manufactured by Munson (Utica,N.Y.) can also be used, as can a standard document shredder as found inmany offices.

The cellulosic or lignocellulosic material is then sheared with a rotarycutter, such as the one manufactured by Sprout, Waldron Companies, asdescribed in Perry's Chem. Eng. Handbook, 6th Ed., at 8-29 (1984).Although other settings can be used, the spacing between the rotatingknives and bed knives of the rotary cutter is typically set to 0.020″ orless, and blade rotation is set to 750 rpm or more. The rotary cuttercan be cooled to 100° C. or lower during the process, for example, usinga water jacket.

The texturized material is passed through a discharge screen. Largerscreens (e.g., up to 6 mm) can be used in large-scale production. Thecellulosic or lignocellulosic feedstock is generally kept in contactwith the blades of the rotary cutter until the fibers are pulled apart;smaller screens (e.g., 2 mm mesh) provide longer residence times andmore complete texturization, but can result in lower length/diameter(L/D) aspect ratios. A vacuum drawer can be attached to the screen tomaximize and maintain fiber length/diameter aspect ratio.

The texturized fibrous materials can be directly stored in sealed bagsor may be dried at approximately 105° C. for 4-18 hours (e.g., until themoisture content is less than about 0.5%) immediately before use. FIG. 1is an SEM photograph of texturized newspaper.

Alternative texturizing methods include stone grinding, mechanicalripping or tearing, and other methods whereby the materials internalfibers can be exposed (e.g., pin grinding, air attrition milling).

Uses of Texturized Fibrous Material

Texturized fibrous materials and compositions and composites of suchfibers with other chemicals and chemical formulations can be prepared totake advantage of the material's properties. The materials can be usedto absorb chemicals, for example, potentially absorbing many times theirown weight. Thus, the materials could, for instance, be used to absorbspilled oil, or for clean-up of environmental pollution, for example, inwater, in the air, or on land. Similarly, the material's absorbentproperties, together with its biodegradability, also make them usefulfor delivery of chemicals or chemical formulations. For example, thematerials can be treated with solutions of enzymes or pharmaceuticalssuch as antibiotics, nutrients, or contraceptives, and any necessaryexcipients, for drug delivery (e.g., for treatment of humans or animals,or for use as or in animal feed and/or bedding), as well as withsolutions of fertilizers, herbicides, or pesticides. The materials canoptionally be chemically treated to enhance a specific absorptionproperty. For example, the materials can be treated with silanes torender them lipophilic.

Compositions including texturized materials combined with liquids orparticulate, powdered, or granulated solids can also be prepared. Forexample, texturized materials can be blended with seeds (i.e., with orwithout treatment with a solution of fertilizer, pesticides, etc.),foodstuffs, or bacteria (e.g., bacteria that digest toxins). The ratioof fibrous materials to the other components of the compositions willdepend on the nature of the components and readily be adjusted for aspecific product application.

In some cases, it may be advantageous to associate the texturizedfibrous materials, or compositions or composites of such materials, wisha structure or carrier such as a netting, a membrane, a flotationdevice, a bag, a shell, or a biodegradable substance. Optionally, thestructure of carrier may itself be made of a texturized fibrous material(e.g., a material of the invention), or a composition or compositethereof.

Composites of Texturized Fibrous Material and Resin

Texturized fibrous materials can also be combined with resins to formstrong, lightweight composites. Materials that have been treated withchemicals or chemical formulations, as described above, can similarly becombined with biodegradable or non-biodegradable resins to formcomposites, allowing the introduction of, for example, hydrophilicsubstances into otherwise hydrophobic polymer matrices. Alternatively,the composites including texturized fibrous materials and resin can betreated with chemicals or chemical formulations.

The texturized cellulosic or lignocellulosic material provides thecomposite with strength. The composite may include from about 10% toabout 90%, for example from about 30% to about 70%, of the texturizedcellulosic or lignocellulosic material by weight.

The resin encapsulates the texturized cellulosic or lignocellulosicmaterial in the composites, and helps control the shape of thecomposites. The resin also transfers external loads to the fibrousmaterials and protects the fiber from environmental and structuraldamage. Composites can include, for example, about 10% to about 90%,more preferably about 30% to about 70%, by weight, of the resin.

Resins are used in a variety of applications, for example, in foodpackaging. Food containers made of resins are typically used once, thendiscarded. Examples of resins that are suitably combined with texturizedfibers include polyethylene (including, e.g., low density polyethyleneand high density polyethylene), polypropylene, polystyrene,polycarbonate, polybutylene, thermoplastic polyesters (e.g., PET),polyethers, thermoplastic polyurethane, PVC, polyamides (e.g., nylon)and other resins. It is preferred that the resins have a low melt flowindex. Preferred resins include polyethylene and polypropylene with meltflow indices of less than 3 g/10 min, and more preferably less than 1g/10 min.

The resins can be purchased as virgin material, or obtained as wastematerials, and can be purchased in pelletized or granulated form. Onesource of waste resin is used polyethylene milk bottles. If surfacemoisture is present on the pelletized or granulated resin, however, itshould be dried before use.

The composites can also include coupling agents. The coupling agentshelp to bond the hydrophilic fibers to the hydrophobic resins. Examplesof coupling agents include maleic anhydride modified polyethylenes, suchthose in the FUSABOND® (available from DuPont, Delaware) and POLYBOND®(available from Uniroyal Chemical, Connecticut) series. One suitablecoupling agent is a maleic anhydride modified high density polyethylenesuch as FUSABON® MB 100D.

The composites can also contain additives known to those in the art ofcompounding, such as plasticizers, lubricants, antioxidants,opacificers, heat stabilizers, colorants, flame retardants, biocides,impact modifiers, photostabilizers, and antistatic agents.

The composites can also include inorganic additives such as calciumcarbonate, graphite, asbestos, wollastonite, mica, glass, fiber glass,chalk, silica, talc, ceramic, ground construction waste, tire rubberpowder, carbon fibers, or metal fibers (e.g., aluminum, stainlesssteel). When such additives are included, they are typically present inquantities of from about 0.5% up to about 20-30% by weight. For example,submicron calcium carbonate can be added to the composites of fiber andresin to improve impact modification characteristics or to enhancecomposite strength.

Preparation of Compositions

Compositions containing the texturized cellulosic or lignocellulosicmaterials and chemicals, chemical formulations, or other solids can beprepared, for example, in various immersion, spraying, or blendingapparatuses, including, but not limited to, ribbon blenders, coneblenders, double cone blenders, and Patterson-Kelly “V” blenders.

For example, a composition containing 90% by weight texturizedcellulosic or lignocellulosic material and 10% by weight ammoniumphosphate or sodium bicarbonate can be prepared in a cone blender tocreate a fire-retardant material for absorbing oil.

Preparation of Composites of Texturized Fiber and Resin

Composites of texturized fibrous material and resin can be prepared asfollows. A standard rubber/plastic compounding 2-roll mill is heated to325-400° F. The resin (usually in the form of pellets or granules) isadded to the heated roll mill. After about 5 to 10 minutes, the couplingagent is added to the roll mill. After another five minutes, thetexturized cellulosic or lignocellulosic material is added to the moltenresin/coupling agent mixture. The texturized material is added over aperiod of about 10 minutes.

The composite is removed from the roll mill, cut into sheets and allowedto cool to room temperature. It is then compression molded into plaquesusing standard compression molding techniques.

Alternatively, a mixer, such as a Banbury internal mixer, is chargedwith the ingredients. The ingredients are mixed, while the temperatureis maintained at less than about 190° C. The mixture can then becompression molded.

In another embodiment, the ingredients can be mixed in an extrudermixer, such as a twin-screw extruder equipped with co-rotating screws.The resin and the coupling agent are introduced at the extruder feedthroat; the texturized cellulosic or lignocellulosic material isintroduced about ⅓ of the way down the length of the extruder into themolten resin. The internal temperature of the extruder is maintained atless than about 190° C. At the output, the composite can be, forexample, pelletized by cold strand cutting.

Alternatively, the mixture can first be prepared in a mixer, thentransferred to an extruder.

In another embodiment, the composite can be formed into fibers, usingfiber-forming techniques known to those in the art, or into filamentsfor knitting, warping, weaving, braiding, or making non-wovens. In afurther embodiment, the composite can be made into a film.

Properties of the Composites of Texturized Fibrous Material and Resin

The resulting composites include a network of fibers, encapsulatedwithin a resin matrix. The fibers form a lattice network, which providesthe composite with strength. Since the cellulosic or lignocellulosicmaterial is texturized, the amount of surface area available to bond tothe resin is increased, in comparison to composites prepared withun-texturized cellulosic or lignocellulosic material. The resin binds tothe surfaces of the exposed fibers, creating an intimate blend of thefiber network and the resin matrix. The intimate blending of the fibersand the resin matrix further strengthens the composites.

Uses of the Composites of Texturized Fibrous Material and Resin

The resin/fibrous material composites can be used in a number ofapplications. The composites are strong and light weight; they can beused, for example, as wood substitutes. The resin coating renders thecomposites water-resistant, so they may be used in outdoor applications.For example, the composites may be used to make pallets, which are oftenstored outdoors for extended periods of time, wine staves, rowboats,furniture, skis, and oars. Many other uses are contemplated, includingpanels, pipes, decking materials, boards, housings, sheets, poles,straps, fencing, members, doors, shutters, awnings, shades, signs,frames, window casings, backboards, wallboards, flooring, tiles,railroad ties, forms, trays, tool handles, stalls, bedding, dispensers,staves, films, wraps, totes, barrels, boxes, packing materials, baskets,straps, slips, racks, casings, binders, dividers, walls, indoor andoutdoor carpets, rugs, wovens, and mats, frames, bookcases, sculptures,chairs, tables, desks, art, toys, games, wharves, piers, boats, masts,pollution control products, septic tanks, automotive panels, substrates,computer housings, above- and below-ground electrical casings,furniture, picnic tables, tents, playgrounds, benches, shelters,sporting goods, beds, bedpans, thread, filament, cloth, plaques, trays,hangers, servers, pools, insulation, caskets, bookcovers, clothes,canes, crutches, and other construction, agricultural, materialhandling, transportation, automotive, industrial, environmental, naval,electrical electronic, recreational, medical, textile, and consumerproducts. Numerous other applications are also envisioned. Thecomposites may also be used, for example, as the base or carcass for aveneer product. Moreover, the composites can be, for example, surfacetreated, grooved, milled, shaped, imprinted, textured, compressed,punched, or colored. The surface of the composites can be smooth orrough.

The following examples illustrate certain embodiments and aspects of thepresent invention and not to be construed as limiting the scope thereof.

EXAMPLES Example 1

A 1500 pound skid of virgin, half-gallon juice cartons made ofpolycoated white kraft board was obtained from International Paper. Eachcarton was folded flat.

The cartons were fed into a 3 hp Flinch Baugh shredder at a rate ofapproximately 15 to 20 pounds per hour. The shredder was equipped withtwo rotary blades, each 12″ in length, two fixed blades, and a 0.3″discharge screen. The gap between the rotary and fixed blades was 0.10″.

The output from the shredder, consisting primarily of confetti-likepieces, about 0.1″ to 0.5″ in width and about 0.25″ to 1″ in length, wasthen fed into a Thomas Wiley Mill Model 2D5 rotary cutter. The rotarycutter had four rotary blades, four fixed blades, and a 2 mm dischargescreen. Each blade was approximately 2″ long. The blade gap was set at0.020″.

The rotary cutter sheared the confetti-like pieces across the knifeedges, tearing the pieces apart and releasing a finely texturized fiberat a rate of about one pound per hour. The fiber had an average minimumL/D ratio of between five and 100 or more. The bulk density of thetexturized fiber was on the order of 0.1 g/cc.

Example 2

Composites of texturized fiber and resin were prepared as follows. Astandard rubber/plastic compounding 2-roll mill was heated to 325-400°F. The resin (usually in the form of pellets or granules) was added tothe heated roll mill. After about 5 to 10 minutes, the resin banded onthe rolls (i.e., it melted and fused on the rolls). The coupling agentwas then added to the roll mill. After another five minutes, thetexturized cellulosic or lignocellulosic material was adder to themolten resin/coupling agent mixture. The cellulosic or lignocellulosicfiber was added over a period of about 10 minutes.

The composite was then removed from the roll mill, cut into sheets, andallowed to cool to room temperature. Batches of about 80 g each werecompression molded into 6″×6″×⅛″ plaques using standard compressionmolding techniques.

One composition contained the following ingredients: Composition No. 1Ingredient Amount(g) High density polyethylene¹ 160 Old newspaper² 240Coupling agent³ 8¹Marlex 16007²Texturized using rotary cutter with 2 mm mesh³FUSABOND ® 100D

The plaques were machined into appropriate test specimens and testedaccording to the procedures outlined in the method specified. Threedifferent specimens were tested for each property, and the mean valuefor each test was calculated. The properties of Composition No. 1 are asfollows: Flexural strength (10³ psi) 9.81 (ASTM D790) Flexural modulus(10⁵ psi) 6.27 (ASTM D790)

A second composition contains the following ingredients: Composition No.2 Ingredient Amount(g) High density polyethylene¹ 160 Old magazines² 240Coupling agent³ 8

The properties of Composition No. 2 are as follows: Flexural strength(10³ psi) 9.06 (ASTM D790) Flexural modulus (10⁵ psi) 6.78 (ASTM D790)

A third composition contains the following ingredients: Composition No.3 Ingredient Amount(g) HDPE¹ 160 Fiber paper² 216 3.1 mm texturizedkenaf 24 Coupling agent³ 8

The properties of Composition No. 3 are as follows: Flexural strength(10³ psi) 11.4 (ASTM D790) Flexural modulus (10⁵ psi) 6.41 (ASTM D790)

A fourth composition contains the following ingredients: Composition No.4 Ingredient Amount (g) SUPERFLEX ™ CaCO₃ 33 Fiber^(2,4) 67 HDPE (w/3%compatibilizer)^(1,3) 100⁴Virgin polycoated milk cartons

The properties of Composition No. 4 are as follows: Flexural strength(10⁵ psi) 8.29 (ASTM D790) Ultimate elongation (%) <5 (ASTM D638)Flexural modulus (10⁵ psi) 10.1 (ASTM D790) Notch Izod (ft-lb/in) 1.39(ASTM D256-97)

A fifth composition contains the following ingredients: Composition No.5 Ingredient Amount (parts) SUPERFLEX ™ CaCO₃ 22 Fiber^(2,4) 67 HDPE(w/3% compatibilizer)^(1,3) 100

The properties of Composition No. 5 are as follows: Flexural strength(10⁵ psi) 8.38 (ASTM D790) Ultimate elongation (%) <5 (ASTM D638)Flexural modulus (10⁵ psi) 9.86 (ASTM D790) Notch Izod (ft-lb/in) 1.37(ASTM D256-97)

A sixth composition contains the following ingredients: Composition No.6 Ingredient Amount (parts) ULTRAFLEX ™ CaCO₃ 33 Fiber^(2,4) 67HDPE/compatibilizer^(1,3) 100

The properties of Composition No. 6 are as follows: Flexural strength(10⁵ psi) 7.43 (ASTM D790) Ultimate elongation (%) <5 (ASTM D638)Flexural modulus (10⁵ psi) 11.6 (ASTM D790) Notch Izod (ft-lb/in) 1.27(astm D256-97)

A seventh composition contains the following ingredients: CompositionNo. 7 Ingredient Amount (pbw) HDPE (w/3% compatibilizer)^(3,5) 60Kraftboard² 40⁵HDPE with melt-flow index <1

The properties of Composition No. 7 are as follows: Flexural Strength(10⁵ psi) 7.79 (ASTM D790) Ultimate elongation (%) <5 (ASTM D638)Flexural Modulus (10⁵ psi) 7.19 (ASTM D790)other embodiments are within the claims.

1-53. (canceled)
 54. A method comprising: providing a fibrous materialincluding fibers comprising a cellulosic or lignocellulosic material,the fibrous material having a bulk density less than about 0.5 g/cm³,and wherein at least about 50 percent of the fibers have alength/diameter ratio of at least about 5; and combining the fibrousmaterial with a bacterium and/or an enzyme.
 55. The method of claim 54,wherein the cellulosic or lignocellulosic material has been sheared witha rotary cutter.
 56. The method of claim 54, wherein the bacterium iscombined with the cellulosic or lignocellulosic material.
 57. The methodof claim 54, wherein the enzyme is combined with the cellulosic orlignocellulosic material.
 58. The method of claim 54, wherein thecellulosic or lignocellulosic material is selected from the groupconsisting of paper, paper products, byproducts of paper manufacture,newsprint, effluent from paper manufacture, wood, wood fibers,wood-related materials, kenaf, grasses, rice hulls, bagasse, cotton,jute, hemp, flax, bamboo bast fibers, bamboo core fibers, leaf plants,sisal, abaca, agricultural fibers, cereal straw, corn cobs, rice hulls,coconut hair, offal, rags, and mixtures thereof.
 59. The method of claim54, wherein the cellulosic or lignocellulosic material comprisesagricultural fibers.
 60. The method of claim 54, wherein at least about50% of the fibers have a length/diameter ratio of at least about
 10. 61.The method of claim 54, wherein at least about 50% of the fibers have alength/diameter ratio of at least about
 25. 62. The method of claim 54,wherein the cellulosic or lignocellulosic material has been sheared tothe extent that it has a bulk density less than about 0.2 g/cm³.